The proper usage of diplexer and duplexer?

Diplexer is a network that splits a signal to two or more laods,dependent on frequency.Often a diplexer is used to route signals,based on frequency,to two different receivers.A diplexer can also be used to create a "matched"filter that is non-reflective outside of the intented passband.Duplexer is a three port network tht allows the transmitter and receiver in a radar or communication system to use the same antenna.The duplexer can be as simple as a circulator in low power applications.